Cannot find any Type B's Please point me in right direction..

[ianhager]

The TL inverters are known to nuisance trip when running through their system start up checks and grid timing tests, not in genral! They recommend a 100mA to eradicate this, the new Garage DB is installed as the old 3036 type C/U obviously doesn't supply RCD protection and the customer didn't want it upgraded so opted for the installation of a new 2 way RCD protected garage unit, and yes,
Of course it tripped out when the RCD .5 / 1 and 5 X and functional tests were carried out otherwise It wouldn't of been commissioned would it.... There really are some pretentious * on here....get a grip and get off your pc's and do some work!
If that's not an option and you're not sure....Don't make assumptions..... just ask for clarification!

 

[SibertSolar]

Ian - not sure if you were directing your last comments at me, for asking if it tripped under fault conditions, but just in case you were - it was a genuine question and was not in any slightest way intended to come across as pretentious! The reason I asked is that, if transient/parasitic leakage currents are present, and they contain a pulsed or pure DC component, then they can affect the function of an RCD. A Type-AC RCD's coil will saturate with the presence of either type of DC leakage current component, and therefore never trip under fault conditions. A Type-A RCD's trip coil will be adversely affected in its ability to trip within its normal operating conditions, especially if there is more than 6mA of pulsed DC leakage current present. A pure DC component of the leakage current will prevent a Type-A RCD's trip coil from operating at all. A Type-B RCD has 2 trip coils and is not adversely affected by the presence of either pulsed or pure DC leakage current components.

Andy

 

[mogga]

"Of course it tripped out when the RCD .5 / 1 and 5 X and functional tests were carried out otherwise It wouldn't of been commissioned would it.... There really are some"

please explain exactly how you got an RCD to trip on 0.5 test??????????? there realy are some * on here

 

[moggy1968]

ianhager:
if you ask for advice don't get umbridge when someone gives it in good faith, wether it may be right or wrong (probably right in this case). If you had read the other threads on here re RCD tripping you would see why this question was asked and not embarrassed yourself!!

 

[meeb]

TL's tripping = Capacitive discharge (rails acting as a capacitor). Stick a volt meter on the rails you will get an AC voltage. SMA recommend a type A rcd 100ma per inverter on the circuit as the discharge current is around 82-83ma. The reason for type A is due to their inverters not feeding DC on to the AC.

Put kettle on job done!

 

[anthanth]

Hager 16A 30mA RCBO Type B [ADN116] - £21.50

would this not do????

 

[moggy1968]

no, the type B element on this refers to the MCB element. The RCD element is a type A (it's in the small print!)

 

[infinity]

This was sorted months back! Type B from SIbertSolar. Job Done!

 

[anthanth]

ah ok. can you send me a link for them??

 

[infinity]

go one page back! Its Andy from Sibiert see his icon under his name! PM Him, He knows all there is to know about that side of things and He is very helpful!

 

[SibertSolar]

Actually, that Hager unit is a Type-AC Moggy ;-) hence the price...

Thanks infinity, a positive referral is always appreciated (blush) lol

Anthanth - please do feel free to contact me or send me your ph number and I'll call you if you wish, happy to help if I can

Andy

 

[sambotc]

TL's tripping = Capacitive discharge (rails acting as a capacitor). Stick a volt meter on the rails you will get an AC voltage. SMA recommend a type A rcd 100ma per inverter on the circuit as the discharge current is around 82-83ma. The reason for type A is due to their inverters not feeding DC on to the AC.

Put kettle on job done!

Can somebody confirm whether this is true or not, because for once in my life I actually understand this and it makes sense, I'm sorry to say that I am still struggling to understand why DC current is going to affect AC RCD, or is it just the fact that in a TL inverter with no galvanic isolation it is possible? (although very unlikely ?)

Surely if this was a serious problem, these DC RCD's should be fitted by the manufacturer within the inverter themselves? Is there mention of this in the manual?

 

[moggy1968]

There is a difference of opinion on here about it but the concensus now seems to be that you don't need to fit and RCD at all, unless one is required for other reasons under the 17th so manufacturers putting one on their inverters would be uneccessary.

 

[sambotc]

I understand the problem, as you say it is not necessary to fit an RCD, unless you have TT earth arrangement etc, like my install the other week we talked about. The part I cannot get my head around is why a type A RCD would not be suitable when using a TL inverter?

As I understand it (or not maybe) When using a TL inverter, their may be a fault which can lead to DC to AC leakage across the inverter due to no galvanic isolation, which would mean that a type A RCD would fail to disconnect in the correct time? Is that right, or wrong?

Is their any other reason why a type B RCD is required (regardless of installation requirements as per 17th) rather than a type A?

If the answer is no, then surely the manufacturers have a duty to ensure this cannot happen, as it would not happen with a transformered inverter, so supply DC residual current protection integral to the unit?

I'm struggling to understand why hard to source components are needed for what should be fairly straightforward domestic wiring?

The other comment I refered too above makes far more sense to me, but relates more to the nuisance tripping rather than a safety issue.

Just to add, this is a question because I don't understand, rather than challenging anyone's judgement on the issue which I am not in a position to do. I am just struggling to get an understanding of the problem, even though I understand the solution!

Thanks in advance!

 

[moggy1968]

have a look at sibberts website. there are some useful PDFs on there which might help to explain. It's rather too inviolved to copy onto here!!